Weta Digital’s Marco Spitoni created this trailer for a pie-in-the-sky CGI movie based on the game Half-Life 2. From what you can see in the video, Spitoni’s a very talented artist, with a strong sense of story, scale, and composition. (And Weta Digital is of course best known as the visual effects studio for The Lord of the Rings trilogy, and many other films since.)
A word of warning though, before watching: it will only make you wish that some Hollywood studio would option the Half-Life games. And Hollywood is far from sold on video games making great fodder for film.